Backflow preventor

ABSTRACT

A backflow prevention device for use with a conventional washing machine system that is uniquely designed to automatically disrupt the power to the washing machine should the drain line leading from the washing machine become clogged. The backflow prevention device includes an internally mounted micro switch that is operably interconnected with a portable ground fault circuit interrupter plug that is connected to a duplex outlet. The washing machine is connected to the ground fault circuit interrupter plug so that, upon being actuated, the micro switch will cause a low voltage default to be sent to the ground fault circuit interrupter which triggers it in a manner to automatically cause an interruption of power to the washing machine.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to fluid flow control devices. More specifically, the invention concerns an overflow prevention device that can be attached to the drain line of a conventional clothes washing machine system and is so constructed and arraigned to automatically disable the washing machine in the event that the washing machine drain becomes clogged.

[0003] 2. Discussion of the Prior Art

[0004] The typical prior art washing machine is usually connected to a household waste system through an upright drain conduit that is, in turn, interconnected with the household sewer system. Since the modern washing machine includes automatic features that enable the washing machine to be used in an unattended fashion, the accidental clogging of the waste line leading to the domestic sewer almost always results in the overflow of rather large quantities of water. Accordingly, several types of overflow control devices have been suggested in the past to avoid this undesirable result. Exemplary of these prior art devices is that disclosed in U.S. Pat. No. 4,418,712 issued to Braley. The Braley invention includes a conductivity pressure sensor that is placed within the drain or standpipe of the washing machine system for sensing the height of liquid therein. The invention further includes a ground fault circuit interrupter and an optional audible alarm both of which can be operably interconnected with the pressure sensor.

[0005] Another type of overflow control device is described in U.S. Pat. No. 5,028,910 issued to Meacham et al. The Meacham patent discloses an overflow device that includes a vertical offset standpipe extending from a conventional standpipe. The offset standpipe has a flow-actuated switch disposed there within that is engaged when the water level rises in the offset standpipe.

[0006] The patent to Mills, U.S. Pat. No. 5,125,247 discloses a device that is somewhat similar to the Meacham device. However, the flow-actuated switch of the Mills device is located in the main standpipe and not in a secondary standpipe.

[0007] The apparatus of the present invention overcomes many of the drawbacks of the prior art overflow control systems and, in one form, includes a backflow preventor having an inflow end and an outflow end. The outflow end is receivable within a drainpipe such as a two-inch plastic standpipe of the character typically used as a washing machine drain. The inflow end of the device, which includes a stepped outer surface to accommodate drain hoses of various sizes, is sealably connected to the washing machine drain hose. A swing type check valve or flapper is mounted internally of the device. The valve is pushed open when water flows from the washing machine to the drain in a normal fashion. However, if the drain backs up and the water flow reverses direction the flapper is pushed closed. This drain backup also causes a strategically located plunger to move upwardly against the urging of a biasing means. Upward movement of the plunger operates an internally mounted micro switch that is operably connected to a portable ground fault circuit interrupter plug. The washing machine is connected to the ground fault circuit interrupter plug, which, in turn, is connected to a conventional duplex wall outlet. With this novel arrangement, when the flapper is closed and backflow pressure from the drain builds up in the outflow end of the valve, the switch is actuated by the upward movement of the plunger. Actuation of the switch causes a low voltage default which triggers the ground fault circuit interrupter, thereby interrupting power to the washing machine.

SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to provide a backflow prevention device of simple construction that can be used with a conventional washing machine system and one which is uniquely designed to automatically disrupt the power to the washing machine should the drain line leading from the washing machine become clogged.

[0009] Another object of the invention is to provide a backflow prevention device of the aforementioned character that is reliable in operation and easy to connect to washing machine drain hoses of various sizes. More particularly, the inflow end of the backflow prevention device includes a stepped outer surface that will accommodate drain hoses of various sizes.

[0010] Another object of the invention is to provide a backflow prevention device as described in the preceding paragraphs that includes an internally mounted micro switch that is actuated upon the washing machine drain becoming clogged. The micro switch is operably interconnected with a portable ground fault circuit interrupter plug that is connected to a duplex outlet and to which the washing machine is connected. Upon actuation, the switch causes a low voltage default to be sent to the ground fault circuit interrupter that triggers the ground fault circuit interrupter thereby automatically causing an interruption of power to the washing machine.

[0011] Another object of the invention is to provide a backflow prevention device of the character described that includes a generally cylindrical connector member having an inflow end and an outflow end. The outflow end is sealably receivable in the standpipe used as the washing machine drain. The outflow end includes an O-ring type seal for sealing the joint between the sleeve and the outflow end so that the backflow prevention device can be easily removed from the standpipe when it is necessary to clear blockages in the washing machine drain system.

[0012] Another object of the invention is to provide a backflow prevention device that is easy to install and one that can be used with almost any type of conventional commercially available washing machine and like appliance.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a generally perspective view showing the device of the invention interconnected with a conventional washing machine system.

[0014]FIG. 2 is a greatly enlarged, generally perspective view of one form of the backflow prevention device of the invention.

[0015]FIG. 3 is an enlarged, cross-sectional view of the backflow prevention device shown in FIG. 2.

[0016]FIG. 4 is a generally perspective, exploded view of the backflow prevention device shown in FIG. 2.

DESCRIPTION OF THE INVENTION

[0017] Referring to the drawings and particularly to FIGS. 1 and 2, one form of the invention can be seen to comprise in combination a washing machine 10 powered from an electrical outlet 12 via current flowing through an electric circuit and a backflow prevention system generally designated by the numeral 14. The washing machine 10 is adapted to receive water from a water supply (not shown) at predetermined intervals in a washing cycle and to remove the water through a drain hose 16 at predetermined intervals in the washing cycle. A standpipe 18 is interposed between the washing machine 10 and the household drainage system for conveying water to the household drainage system.

[0018] In the present form of the invention, the backflow prevention device comprises a hollow housing 20 defining a flow passageway 22 having an inlet 24 (FIG. 3) interconnected with the drain hose 16 and an outlet 26 interconnected with standpipe 18. A valve, such as a flapper valve assembly 28, is mounted within flow passageway 22 intermediate the inlet and the outlet. Valve assembly 28, which comprises a valve member 28 a and a cooperating gasket 28 b, is movable from a first closed position shown by the solid lines in FIG. 3 to a second open position shown by the phantom lines in FIG. 3 in response to water flowing into the inlet. Valve 28 is movable from the second open position to the first closed position in response to water flowing from outlet 26 toward inlet 24 in the direction of arrow 27 of FIG. 3. A valve biasing means, which is connected to the hollow housing, yieldably urges the valve toward said first closed position.

[0019] Forming an important feature of the backflow prevention device of the present invention is switch means, which is carried by housing 20 and is operably associated with the electric circuit for interrupting the flow of current through the electric circuit upon actuation of the switch means. The backflow prevention device also includes operating means carried by housing 20. The operating means is operably associated with the switch means and functions to operate the switch means in response to water flowing from outlet 26 toward inlet 24. The construction and operation of these important features of the invention will be described in greater detail the paragraphs which follow.

[0020] Referring particularly to FIG. 3, it is to be noted that hollow-housing 10 includes first and second side chambers 30 and 32 that are in communication with flow passageway 22. In the present form of the invention, the operating means comprises a plunger 34 that is reciprocally movable within side chamber 30 from a first position to a second position in response to water flowing from outlet 26 toward inlet 24 (see also FIG. 4). An elastomeric O-ring 35 prevents fluid leakage past the plunger. Plunger 34 includes an elongated, outwardly protruding operating stem 34 a, the purpose of which will presently be described. As best seen in FIG. 3, the upper portion of chamber 30 is closed by a cap 38 having a central aperture 38 a through which stem 34 a protrudes.

[0021] Connected to cap 38 is a hollow switch housing 40 within which the switch means of the invention is mounted. The switch means here comprises a readily commercially available micro switch 42 that is operably associated with the electric circuit of the apparatus for interrupting the flow of current upon actuation of the micro switch by the operating means of the invention. Micro switch 42 is available from various commercial sources such as Micro Switch Co. of Freeport, Ill. Micro switch 42 includes a downwardly extending operating arm 42 a that is engageable by stem 34 a as plunger 34 is moved upwardly within chamber 30 in response to fluid flowing from outlet 26 toward the plunger in the direction of arrow 27 (FIG. 3). As illustrated in FIG. 1, micro switch 42 is operably interconnected by means of the electrical conduit 44 with a portable ground fault circuit interrupter (GFCI) plug 46 that also forms a part of the circuit interrupting means of the invention.

[0022] GFCI plug 46 is readily commercially available from various sources, including TRC of Clearwater, Fla. The details of the construction and operation of plug 46 can be obtained from the TRC Company and are also described in U.S. Pat. No. 4,567,456 issued to Legatti. Reference should be made to this patent for an understanding of the operation of GFCI plug 46. As shown in FIG. 1, plug 46, which is plugged into duplex outlet 12, is constructed and arranged to receive the power plug 10 a of the washing machine 10 which is, in turn, connected to the washing machine power cord 10 a. With the arrangement shown in FIG. 1, the reset switches 46 a of the GFI plug are readily accessible. As previously mentioned, micro switch 42 is operably interconnected with plug 46 by electrical conduit 44. More particularly, the wires of conduit 44 are connected at one end to the upper terminals of the micro switch and are connected at the other end in parallel to the leads running to the reset switches 46 a of the GFI plug 46. This electrical interconnection of micro switch 42 with the GFI plug 46 is well understood by those skilled in the art.

[0023] In using the apparatus of the invention, a waste line connector means, which here comprises a generally cylindrically shaped member or connector collar 50 is connected to the upper open end of the standpipe 18. As best seen in FIG. 3, member 50 has an open top portion and an inwardly tapering sidewall that is sealably receivable within standpipe 18 and a manner shown in FIG. 1. With a connector collar thusly sealably inserted into the upper end of the standpipe 18 and locked in place by the bayonet type locking arrangement 51, the lower cylindrical portion 20 a of hollow housing 20 is inserted into the connector collar 50 in the manner shown in FIG. 3. As shown in FIG. 3, hollow-housing 20 includes a flange 20 b that engages the upper portion 50 a of collar 50 when the lower portion of the hollow housing is fully seated within the connector collar. An elastomeric O-ring 52 and is disposed between the flange 20 b and upper portion 50 a to prevent leakage between the mating components.

[0024] With the hollow housing 20 mated with the standpipe 18 in the manner described in the preceding paragraph, the water supply connector means of the invention is connected to the upper portion of second chamber 32 in the manner best seen in FIG. 3. In the present form of the invention, the water supply connector means comprises a hollow member 54 made up of a plurality of interconnected, generally cylindrically shaped segments of different outside diameters, such as segments 54 a, 54 b, 54 c, 54 d and 54 e. The novel construction of member 54 permits the convenient interconnection therewith of drain lines of various inside diameters.

[0025] During the normal operation of the washing machine, as the water flows from the washing machine to the drain hose 16, flapper valve 28 is pushed open against the urging of a flapper valve biasing means shown here as a torsion spring 56. However, if the drain becomes clogged causing the drain water to back up and to flow in the direction of the arrow 27, the flapper valve 28 will be pushed closed in the manner shown by the solid lines in FIG. 3. This drain backup and reverse flow of the drain water also causes plunger 34 to move upwardly against the urging of a plunger biasing means shown here as a coil spring 58. Upward movement of the plunger causes the plunger stem 34 a to engage the downwardly extending switch operating arm 42 a in a manner to actuate micro switch 42, which as previously mentioned, is operably associated with the portable ground fault circuit interrupter plug 46. As also previously mentioned, washing machine 10 is electrically connected to the ground fault circuit interrupter plug, which, in turn, is connected to the conventional duplex wall outlet 12. Actuation of micro switch 42 causes a low voltage default to be sent to the ground fault circuit interrupter, which triggers the ground fault circuit interrupter causing an automatic interruption of the power flowing to the washing machine.

[0026] Following an interruption in power, the backflow prevention body 20 can be easily removed from the connector collar 50 to enable the clog in the drain system to be cleared. Once the clog is cleared, body 20 can be once again sealably interconnected with connector collar 50 and the ground fault circuit interrupter plug 46 can be reset using reset switches 46 a. This done, normal operation of the washing machine can once again commence.

[0027] Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims. 

We claim:
 1. In combination, a washing machine powered from an electrical outlet by current flowing to the washing machine through an electric circuit, the washing machine receiving water from a water supply and conveying wastewater to a household drainage system via a drain hose connected to the washing machine, and a backflow prevention system comprising: (a) circuit interrupting means disposed between the electrical outlet and the washing machine for interrupting current flowing to the washing machine through the electric circuit; (b) a standpipe interposed between the washing machine and the household drainage system for conveying the wastewater there through; (c) a hollow housing defining a flow passageway having an inlet interconnected with the drain hose and an outlet interconnected with said standpipe; (d) switch means carried by said housing and operably associated with said circuit interrupting means for causing a low voltage default to be sent to said circuit interrupting means; and (e) operating means carried by said housing and operably associated with said switch means for causing said switch means to send a low voltage default to said circuit interrupting means in response to water flowing from said outlet toward said inlet.
 2. The combination as defined in claim 1 further including a valve mounted within said flow passageway intermediate said inlet and said outlet, said valve being movable from a first closed position to a second open position in response to water flowing into said inlet and being movable from said second open position to said first closed position in response to water flowing from said outlet toward said inlet;
 3. The combination as defined in claim 2 further including valve biasing means connected to said hollow housing for yieldably urging said valve toward said first closed position.
 4. The combination as defined in claim 2 in which said hollow housing includes a first chamber in communication with said flow passageway and in which said operating means comprises a plunger reciprocally movable within said first chamber from a first position to a second position in response to water flowing from said outlet toward said inlet.
 5. The combination as defined in claim 2 in which said circuit-interrupting means comprises a portable ground fault circuit interrupter plug connected to the electrical outlet.
 6. The combination as defined in claim 2 further including a connector member disposed between said hollow housing and said standpipe, said hollow housing being sealably received within said connector member.
 7. In combination, a washing machine powered from an electrical outlet by current flowing to the washing machine through an electric circuit, said washing machine receiving water from a water supply and conveying the water to a household drainage system via a drain hose connected to the washing machine, and a backflow prevention system comprising: (a) circuit interrupting means disposed between the electrical outlet and the washing machine for interrupting current flowing through the electric circuit toward the washing machine; (b) a standpipe interposed between the washing machine and the household drainage system for conveying the wastewater there through; (c) a hollow housing defining a flow passageway having an inlet interconnected with the drain hose and an outlet interconnected with said standpipe, said hollow housing and having first and second side chambers; (d) a valve mounted within said flow passageway intermediate said inlet and said outlet, said valve being movable from a first closed position to a second open position in response to water flowing into said inlet and being movable from said second open position to said first closed position in response to water flowing from said outlet toward said inlet; (e) switch means carried by said housing and operably associated with said circuit interrupting means for causing a low voltage default to be sent to said circuit interrupting means upon actuation of said switch means; and (f) operating means carried by said housing and operably associated with said switch means for actuating said switch means to cause said switch means to send a low voltage default to said circuit interrupting means in response to water flowing from said outlet toward said inlet.
 8. The combination as defined in claim 7, further including switch biasing means connected to said hollow housing for yieldably urging said valve toward said first closed position.
 9. The combination as defined in claim 7 in which said circuit-interrupting means comprises a portable ground fault circuit interrupter plug connected to the electrical outlet.
 10. The combination as defined in claim 7 in which said operating means comprises a plunger reciprocally movable within said first side chamber, said plunger having an operating stem extending there from.
 11. The combination as defined in claim 7, further including a closure cap closing said first chamber, said closure cap having an aperture therein for receiving said stem of said plunger.
 12. The combination as defined in claim 11, further including a hollow switch housing connected to said closure cap, said switch means being disposed within said switch housing.
 13. The combination as defined in claim 12 in which said switch means comprises a micro switch.
 14. The combination as defined in claim 13 in which said micro switch includes a downwardly depending operating arm engageable by said stem of said plunger to actuate said micro switch.
 15. A backflow prevention system operably associated with a washing machine powered from an electrical outlet via current flowing through an electric circuit, said washing machine receiving water from a water supply at predetermined intervals in a washing cycle and removing the water at predetermined intervals in the washing cycle through a drain hose connected to a household drainage system, said backflow prevention system comprising: (a) circuit interrupting means disposed between the electrical outlet and the washing machine for interrupting current flowing through the electric circuit toward the washing machine, said circuit interrupting means comprising a portable ground fault circuit interrupter plug connected to the electrical outlet; (b) a standpipe interposed between the washing machine and the drainage system for conveying the wastewater there through, said standpipe having an open upper end; (c) a connector member connected to the open end of said standpipe; (d) a hollow housing connected to said connector member, said hollow housing defining a flow passageway having an inlet interconnected with the drain hose and an outlet interconnected with said connector member, said hollow housing having first and second side chambers; (e) a valve mounted within said flow passageway intermediate said inlet and said outlet, said valve being movable from a first closed position to a second open position in response to water flowing into said inlet and being movable from said second open position to said first closed position in response to water flowing from said outlet toward said inlet; (f) a micro switch carried by said housing and operably associated with said circuit interrupting means for causing a low voltage default to be sent to said circuit-interrupting means upon actuation of said micro switch; (g) operating means carried by said housing and operably associated with said switch means for actuating said switch means in response to water flowing from said outlet toward said inlet, said operating means comprising a plunger reciprocally movable within said the first side chamber from a first position to a second position in response to water flowing from said outlet toward said inlet, said plunger having an operating stem extending there from; and (h) water supply connector means connected to said housing proximate said second chamber, said water supply connector means comprising a hollow member made up of a plurality of interconnected, generally cylindrically shaped segments of different outside diameters.
 16. The combination as defined in claim 15, further including plunger-biasing means carried within said first side chamber for yieldably resisting movement of said plunger toward said second position.
 17. The combination as defined in claim 15, further including an elastomeric O-ring disposed between said connector member and said hollow housing.
 18. The combination as defined in claim 15, further including a closure cap closing said first chamber, said closure cap having an aperture therein for receiving said stem of said plunger.
 19. The combination as defined in claim 18, further including a hollow switch housing connected to said closure cap, said micro switch being disposed within said switch housing.
 20. The combination as defined in claim 19 in which said micro switch includes a downwardly depending operating arm engageable by said stem of said plunger to actuate said micro switch. 